This proposal seeks funds to support the Plasmid Biology 2002 Symposium to be held in Pittsburgh from 22nd to 28th June 2002. The goals of the meeting are to bring together scientists working in all the areas of plasmid biology to discuss the latest progress and advances in the field. Plasmids represent a unique group of genetic elements found in prokaryotes, eukaryotes and archaeon. They are a major source of genetic discovery in bacteria and are responsible for the spread of a variety of genes in nature, including those encoding antibiotic resistance and those involved in bacterial pathogenicity. Since many plasmids are conjugative or mobilizable, they contribute to the evolution of organisms that are resistant to a number of antibiotics, produce toxins or have increased virulence. Plasmids also serve as models for basic biological studies such as replication, gene expression, and recombination, to name a few. Plasmids are also important tools in industries related to medicine/genomi cs, biotechnology, agriculture and environment. Vigorous studies on plasmid biology are necessary for a better understanding of the molecular mechanisms involved in their persistence and spread in nature. Plasma Biology 2002 represents a continuation of the bi-annual symposia held to discuss the highlights of major advances in this field every two years. The meeting will include a discussion of all aspects of plasmid biology such as their replication and maintenance, transfer, their role as a source of horizontal gene pool, including antibiotic resistance and virulence genes, involvement in bacterial pathogenicity, and evolution and ecology. We anticipate attendance by approximately 150 scientists. There is no similar meeting that covers all of the areas of plasmid biology. This meeting serves the international plasmid biology community and provides an excellent forum for change of ideas that are critical for the continued advances in the field. Participants in the past meeting have in cluded leaders in the field as well as younger scientists such as graduate students and postdoctoral fellows. The meeting will include invited speakers as well as speakers selected on the basis of submitted abstracts. NIH funds are requested to partly defray such costs as organization expenses, brochure and abstract book preparation, travel expenses and boarding and lodging expenses of several participants.